參數(shù)資料
型號: MC68HC05CT4FN
廠商: MOTOROLA INC
元件分類: 微控制器/微處理器
英文描述: 8-BIT, MROM, 2.048 MHz, MICROCONTROLLER, PQCC44
封裝: PLASTIC, LCC-44
文件頁數(shù): 100/142頁
文件大?。?/td> 624K
代理商: MC68HC05CT4FN
NON-DISCLOSURE
AGREEMENT
REQUIRED
16-Bit Timer
General Release Specification
MC68HC05CT4 Rev. 2.0
60
16-Bit Timer
MOTOROLA
8.3 Counter Register
The key element in the programmable timer is a 16-bit, free-running
counter or counter register, preceded by a prescaler that divides the
internal processor clock by four. The prescaler gives the timer a
resolution of 2.0 microseconds if the internal bus clock is 2.0 MHz. The
counter is incremented during the low portion of the internal bus clock.
Software can read the counter at any time without affecting its value.
The double-byte, free-running counter can be read from either of two
locations, $18–$19 (counter register) or $1A–$1B (counter alternate
register). If a read of the free-running counter or counter alternate
register is from the least significant byte (LSB) ($19, $1B), the LSB
receives the count value at the time of the read. If a read of the free-
running counter or counter alternate register first addresses the most
significant byte (MSB) ($18, $1A), the LSB ($19, $1B) is transferred to a
buffer. This buffer value remains fixed after the first MSB read, even if
the user reads the MSB several times. This buffer is accessed when
reading the free-running counter or counter alternate register LSB ($19
or $1B) and, thus, completes a read sequence of the total counter value.
In reading either the free-running counter or counter alternate register, if
the MSB is read, the LSB also must be read to complete the sequence.
The counter alternate register differs from the counter register in one
respect: a read of the counter register MSB can clear the timer overflow
flag (TOF). The counter alternate register can be read at any time
without the possibility of missing timer overflow interrupts due to clearing
of the TOF.
相關(guān)PDF資料
PDF描述
MC68HC05J1P 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDIP20
MC68HC05J1CDW 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDSO20
MC68HC05J1DW 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDSO20
MC68HC05J1CP 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDIP20
MC68HC05JB4DWR2 8-BIT, MROM, 3 MHz, MICROCONTROLLER, PDSO28
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68HC05D9 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:8-bit microcomputer with PWM outputs and LED drive
MC68HC05E0 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit
MC68HC05E0FN 制造商:未知廠家 制造商全稱:未知廠家 功能描述:8-Bit Microcontroller
MC68HC05E16 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:16256 bytes of user ROM, 320bytes of EPROM and 352 bytes of RAM
MC68HC05E16/D 制造商:MOTOROLA 制造商全稱:Motorola, Inc 功能描述:16256 bytes of user ROM, 320bytes of EPROM and 352 bytes of RAM